modules/misc/inhibit.c

   1 /*****************************************************************************
   2  * inhibit.c : prevents the computer from suspending when VLC is playing
   3  *****************************************************************************
   4  * Copyright © 2007 Rafaël Carré
   5  * $Id$
   6  *
   7  * Author: Rafaël Carré <funman@videolanorg>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*
  25  * Based on freedesktop Power Management Specification version 0.2
  26  * http://people.freedesktop.org/~hughsient/temp/power-management-spec-0.2.html
  27  */
  28
  29 /*****************************************************************************
  30  * Preamble
  31  *****************************************************************************/
  32
  33 #ifdef HAVE_CONFIG_H
  34 # include "config.h"
  35 #endif
  36
  37 #include <vlc_common.h>
  38 #include <vlc_plugin.h>
  39 #include <vlc_input.h>
  40 #include <vlc_interface.h>
  41
  42 #include <dbus/dbus.h>
  43
  44 #define PM_SERVICE   "org.freedesktop.PowerManagement"
  45 #define PM_PATH      "/org/freedesktop/PowerManagement/Inhibit"
  46 #define PM_INTERFACE "org.freedesktop.PowerManagement.Inhibit"
  47
  48 /*****************************************************************************
  49  * Local prototypes
  50  *****************************************************************************/
  51 static int  Activate     ( vlc_object_t * );
  52 static void Deactivate   ( vlc_object_t * );
  53
  54 static void Run          ( intf_thread_t *p_intf );
  55
  56 static int Inhibit( intf_thread_t *p_intf );
  57 static int UnInhibit( intf_thread_t *p_intf );
  58
  59 struct intf_sys_t
  60 {
  61     DBusConnection  *p_conn;
  62     dbus_uint32_t   i_cookie;
  63 };
  64
  65 /*****************************************************************************
  66  * Module descriptor
  67  *****************************************************************************/
  68 vlc_module_begin ()
  69     set_description( N_("Power Management Inhibitor") )
  70     set_capability( "interface", 0 )
  71     set_callbacks( Activate, Deactivate )
  72 vlc_module_end ()
  73
  74 /*****************************************************************************
  75  * Activate: initialize and create stuff
  76  *****************************************************************************/
  77 static int Activate( vlc_object_t *p_this )
  78 {
  79     intf_thread_t *p_intf = (intf_thread_t*)p_this;
  80     DBusError     error;
  81
  82     p_intf->pf_run = Run;
  83     p_intf->p_sys = (intf_sys_t *) calloc( 1, sizeof( intf_sys_t ) );
  84     if( !p_intf->p_sys )
  85         return VLC_ENOMEM;
  86
  87     p_intf->p_sys->i_cookie = 0;
  88
  89     dbus_error_init( &error );
  90     p_intf->p_sys->p_conn = dbus_bus_get( DBUS_BUS_SESSION, &error );
  91     if( !p_intf->p_sys->p_conn )
  92     {
  93         msg_Err( p_this, "Failed to connect to the D-Bus session daemon: %s",
  94                 error.message );
  95         dbus_error_free( &error );
  96         free( p_intf->p_sys );
  97         return VLC_EGENERIC;
  98     }
  99
 100     return VLC_SUCCESS;
 101 }
 102
 103 /*****************************************************************************
 104  * Deactivate: uninitialize and cleanup
 105  *****************************************************************************/
 106 static void Deactivate( vlc_object_t *p_this )
 107 {
 108     intf_thread_t *p_intf = (intf_thread_t*)p_this;
 109     if( p_intf->p_sys->i_cookie )
 110         UnInhibit( p_intf );
 111
 112     dbus_connection_unref( p_intf->p_sys->p_conn );
 113     free( p_intf->p_sys );
 114 }
 115
 116 /*****************************************************************************
 117  * Inhibit: Notify the power management daemon that it shouldn't suspend
 118  * the computer because of inactivity
 119  *
 120  * returns false if Out of memory, else true
 121  *****************************************************************************/
 122 static int Inhibit( intf_thread_t *p_intf )
 123 {
 124     DBusConnection *p_conn;
 125     DBusMessage *p_msg;
 126     DBusMessageIter args;
 127     DBusMessage *p_reply;
 128     dbus_uint32_t i_cookie;
 129
 130     p_conn = p_intf->p_sys->p_conn;
 131
 132     p_msg = dbus_message_new_method_call( PM_SERVICE, PM_PATH, PM_INTERFACE,
 133                                           "Inhibit" );
 134     if( !p_msg )
 135         return false;
 136
 137     dbus_message_iter_init_append( p_msg, &args );
 138
 139     char *psz_app = strdup( PACKAGE );
 140     if( !psz_app ||
 141         !dbus_message_iter_append_basic( &args, DBUS_TYPE_STRING, &psz_app ) )
 142     {
 143         free( psz_app );
 144         dbus_message_unref( p_msg );
 145         return false;
 146     }
 147     free( psz_app );
 148
 149     char *psz_inhibit_reason = strdup( "Playing some media." );
 150     if( !psz_inhibit_reason )
 151     {
 152         dbus_message_unref( p_msg );
 153         return false;
 154     }
 155     if( !dbus_message_iter_append_basic( &args, DBUS_TYPE_STRING,
 156                                          &psz_inhibit_reason ) )
 157     {
 158         free( psz_inhibit_reason );
 159         dbus_message_unref( p_msg );
 160         return false;
 161     }
 162     free( psz_inhibit_reason );
 163
 164     p_reply = dbus_connection_send_with_reply_and_block( p_conn, p_msg,
 165         50, NULL ); /* blocks 50ms maximum */
 166     dbus_message_unref( p_msg );
 167     if( p_reply == NULL )
 168     {   /* g-p-m is not active, or too slow. Better luck next time? */
 169         return true;
 170     }
 171
 172     /* extract the cookie from the reply */
 173     if( dbus_message_get_args( p_reply, NULL,
 174             DBUS_TYPE_UINT32, &i_cookie,
 175             DBUS_TYPE_INVALID ) == FALSE )
 176     {
 177         return false;
 178     }
 179
 180     /* Save the cookie */
 181     p_intf->p_sys->i_cookie = i_cookie;
 182     return true;
 183 }
 184
 185 /*****************************************************************************
 186  * UnInhibit: Notify the power management daemon that we aren't active anymore
 187  *
 188  * returns false if Out of memory, else true
 189  *****************************************************************************/
 190 static int UnInhibit( intf_thread_t *p_intf )
 191 {
 192     DBusConnection *p_conn;
 193     DBusMessage *p_msg;
 194     DBusMessageIter args;
 195     dbus_uint32_t i_cookie;
 196
 197     p_conn = p_intf->p_sys->p_conn;
 198
 199     p_msg = dbus_message_new_method_call( PM_SERVICE, PM_PATH, PM_INTERFACE,
 200                                           "UnInhibit" );
 201     if( !p_msg )
 202         return false;
 203
 204     dbus_message_iter_init_append( p_msg, &args );
 205
 206     i_cookie = p_intf->p_sys->i_cookie;
 207     if( !dbus_message_iter_append_basic( &args, DBUS_TYPE_UINT32, &i_cookie ) )
 208     {
 209         dbus_message_unref( p_msg );
 210         return false;
 211     }
 212
 213     if( !dbus_connection_send( p_conn, p_msg, NULL ) )
 214         return false;
 215     dbus_connection_flush( p_conn );
 216
 217     dbus_message_unref( p_msg );
 218
 219     p_intf->p_sys->i_cookie = 0;
 220     return true;
 221 }
 222
 223 /*****************************************************************************
 224  * Run: main thread
 225  *****************************************************************************/
 226 static void Run( intf_thread_t *p_intf )
 227 {
 228     for( ;; )
 229     {
 230         input_thread_t *p_input;
 231
 232         /* Check playing state every 30 seconds */
 233         msleep( 30 * CLOCK_FREQ );
 234
 235         p_input = vlc_object_find( p_intf, VLC_OBJECT_INPUT, FIND_ANYWHERE );
 236         if( p_input )
 237         {
 238             const int i_state = var_GetInteger( p_input, "state" );
 239             vlc_object_release( p_input );
 240
 241             if( PLAYING_S == i_state )
 242             {
 243                if( !p_intf->p_sys->i_cookie )
 244                {
 245                    if( !Inhibit( p_intf ) )
 246                        break;
 247                }
 248             }
 249             else if( p_intf->p_sys->i_cookie )
 250             {
 251                 if( !UnInhibit( p_intf ) )
 252                     break;
 253             }
 254         }
 255         else if( p_intf->p_sys->i_cookie )
 256         {
 257             if( !UnInhibit( p_intf ) )
 258                 break;
 259         }
 260     }
 261 }